This invention relates to an alternate manually and electrically actuated bolt, and more specifically, to such a bolt assembly having unique mechanisms therein for accomplishing the two distinct manual and electrically driven functions thereof in an improved and separable manner while eliminating the disadvantages of the prior constructions. According to one concept which may be incorporated as one embodiment of the present invention, the bolt may be driven to and between its extended and retracted positions alternately by either the manual or electrical drive, but more important, when moved into either extended or retracted position by the electrical drive, a preferably major portion of the electrical drive automatically effectively disconnects from the bolt so that as an end result, when the bolt is in either of its extended or retracted positions, there is automatically presented a free choice of either manual or electrical actuation as to next moving the bolt and the bolt movement may be freely accomplished by the chosen means without disconnecting or otherwise involving the other. According to another concept which may be incorporated as another embodiment of the present invention, the bolt may again be alternately driven between its extended and retracted positions by either the manual or electrical drive, but if the electrical drive should fail during use of the electrical drive wherein the bolt is positioned intermediate its extended and retracted positions, for instance, due to electric power interruption, the overall assembly is arranged such that by a simple manipulation, a major portion of the electrical drive mechanism including at least a major part of the gear means may be effectively disconnected from the bolt so as to permit the usual manual drive to complete the bolt movement to either of its extended or retracted positions. Of course, the optimum is the incorporation of both concepts in the same embodiment of the present invention so that a free choice of either manual or electrical actuation is presented when the bolt is in either of its extended or retracted positions, yet when the bolt is under electrical actuation intermediate its extended and retracted positions with electrical failure occurring, the bolt may be quickly moved into either of its positions by the manual actuation.
Various bolt assemblies have heretofor been provided wherein the bolts thereof are electrically actuated in one manner or another. Commonly, two basic classes of bolts are involved, the far less secure spring-bolts which are spring urged to extended position and retracted against the spring urging by simple electrically actuated solenoids, and deadbolts which must be positively actuated in both directions between extended and retracted positions through gear connected electric motors. It is this latter class of bolt assemblies with which the present invention is involved and which provides far greater security than the spring-bolt assemblies.
In the provision of deadbolt assemblies wherein the bolt is movable between extended and retracted positions by a reversible electric motor, to appreciate the problems involved, it must be remembered that total bolt movement in either direction is only approximately one inch, sometimes slightly more and sometimes slightly less depending upon the particular assembly. Thus, in connecting a reversible electric motor theretofor producing such relatively slight movement, the basic rotatable movement of the electric motor must be quite extensively reduced through various gear reduction means for ultimate operable connection to the bolt. The prime consideration is that with this extensive gear reduction between the electric motor and the bolt for transferring the necessary motion, it is virtually impossible to otherwise move the bolt, say by some form of manual actuation thereof, for so long as the motor connecting gear means remains effectively connected with the bolt.
However, it is well known that there is always presented the possibility of electrical power failure which could temporarily disable the electric motor drive during which it would be impossible to move the bolt unless the capability of bolt manual actuation is incorporated in the assembly. Furthermore, there are many instances where deadbolt assemblies solely driven by electric motors are not desirable, but rather alternate manually and electrically actuated assemblies are required. This presents the problem of just how to provide a deadbolt assembly which may be alternately manually and electrically actuated without the mechanism for accomplishing the one form of actuation prohibitively affecting the mechanism for accomplishing the other form of actuation.
Certain of the prior constructions have incorporated alternate manual and electrical actuation of deadbolts. The electric motors are connected to the deadbolts through the severe gear reduction arrangement for electrical actuation and the means for manually actuating the deadbolts have usually been arranged and connected in a manner similar to that of totally manually actuated deadbolts where electrical actuation is not involved. In order to accommodate manual actuation of the deadbolts during failure of the electrical system, slip clutch means, usually in the form of common friction clutches, are provided within the gear connection of the electric motors at some location near the connections to the deadbolts. Thus, if the electrical system fails, manual actuation of the deadbolts can be accomplished by overcoming the friction drive of the particular clutch through such manual actuation with the clutch thereby eliminating the remainder of the gear connection and eliminating the requirement for movement of the same.
Although this slip or friction clutch bypassing of the main part of the electrical drive and particularly the majority of the gear connection thereof may be satisfactory where electrical actuation is the prime goal of the deadbolt assembly involved and manual actuation is only intended for the temporary electrical energy failure on an emergency basis, it is clearly not satisfactory where the deadbolt assembly is intended for frequent alternate use between manual actuation and electrical actuation. Manual actuation of the deadbolt while being required to cause slippage of the friction clutch in the electrical system can be relatively difficult, and particularly where the friction clutch is of sufficient power transmitting strength to properly function in the electrical system for actuating the deadbolt electrically over a long period of time. For these reasons, improvements are demanded in the deadbolt connections where true alternate manual and electrical actuation thereof is desired.